During a wafer test, a probe card is usually used in a testing equipment for contacting the device under test (DUT) and transferring testing signals in order to obtain electrical properties of the DUT. The probe cards can be classified into a cantilever probe card (CPC) and a vertical probe card (VPC).
FIG. 1-1 and FIG. 1-2 are structural illustrative drawings of a conventional vertical probe card 1 according to the known art. The conventional vertical probe card 1 includes a printed circuit board 2, a space converting layer 3 disposed in one side of the printed circuit board 2, a probe head 4 disposed in one side of the space converting layer 3, and a plurality of probes 5 disposed in the probe head 4. The space converting layer 3 may be replaced by other structures, such as manual wire drawing traces connected between the printed circuit board 2 and a substrate, and the probe head 4 is disposed in one side of the substrate, such that the space converting layer 3 together with the other substitutable structures can be collectively called as a space transformer. When a chip is tested by using the vertical probe card 1, each probe 5 tip is able to be abutting against the test pads of the chip for electrical transmission. Each probe 5 can absorb the reversed stress through elastic deformation itself. The probe head 4 shown in FIG. 1-1 is a probe head having two dies. The probe head 4 includes an upper die 6, a lower die 7, and a locating plate 8. The upper die 6 and the lower die 7 can be combined to each other in order to form a layout space 9 of the probes between them, and the locating plate 8 is disposed within the layout space 9. There are a plurality of holes 10 disposed on the corresponding locations of the probes 5 of the upper die 6, the lower die 7, and the locating plate 8, respectively, wherein the plurality of holes 10 has a size corresponding to a diameter dimension of the probe 5. Hence, when the probes 5 are installed in line assembly, each probe 5 can pass through the corresponding holes 10 of the locating plate 8 and the lower die 7 and remain in a vertical configuration. After that, the locating plate 8 is covered by the upper die 6, such that the probes 5 can pass through the corresponding holes 10 of the upper die 6 to complete the assembly. FIG. 1-2 is a structural illustrative drawing of another conventional vertical probe card 4 having three dies according to the known art, which further includes a middle die 11 (MD) disposed between the upper die 6 and the lower die 7 and can be applied to the probes 5 having a longer length, thereby reducing degree of metalworking and assembly difficulty.
After frequent test operations have been performed on the vertical probe card 1, the probes 5 disposed in the probe head 4 may easily generate wear and abrasions of varying degrees. Hence, replacement and maintenance of the probes 5 are often required. In practice, during the process of replacing the probes 5, the upper die 6 must be removed from probe head 4 first. Then, the probe 5 to be replaced is taken out, and a new probe 5 is inserted thereon once more. However, the size or dimensions of the probes 5 is very small and precise, and the probes 5 are tightly aligned to each other. In addition, the locating plate 8 is a non-fixed or non-stationary structure, and thus the locating plate 8 can be easily turned back if the probe head 4 is removed from the upper die 6, or that the probe 5 is taken out, which may negatively affect other properly working probes 5 so as to be taken out together alongside. As a result, there-insertions of other replacement probes 5 are required, which may increase repair cost and thereby waste maintenance time and labor, especially probe cards having high pin count will be affected more seriously.